The present invention relates to manufacturing a spacing frame for use in forming an insulated arrangement of spaced glass panes from a continuous length of a tubular bar containing granules of hygroscopic or dessicant material of given size. The bar has a wall section forming the inside border surface of the frame, the wall section having openings or passages communicating between the hygroscopic material in the bar and the region between the spaces panes. In particular, the invention is directed to forming corners of the spacing frame by cutting the wall section in a direction transverse to the longitudinal axis of the bar, and bending the bar sections extending between the cuts relative to each other to form the frame corners.
Various frames for spacing glass panes to form an insulated arrangement of spaced glass panes are known and disclosed, for example, in U.S. Pat. Nos. 3,540,118 and 3,380,145, and Canadian Pat. No. 1,006,052. The spacing frames are usually made of relatively light weight metal bar sections. The bar sections may be provided in lengths corresponding to sides of the finished frame, the frame being formed by joining the individual bar sections together by way of special corner connectors or pieces provided at the frame corners, as disclosed in Canadian Pat. No. 1,006,052. The ends of the separate bar sections may abut each other at the frame corners. Further, miter cuts can be made transverse to the longitudinal direction of a tubular bar of given length, thereby forming connected bar sections which can be bent at the miter cuts to form the frame corners, the ends of the tubular bar being joined by a single connecting piece. Such a construction is disclosed in U.S. Pat No. 3,380,145.
The tubular bar sections of the known spacing frames each contain granules of hygroscopic or desiccant material, this material being well known and commercially available. Slots or perforations are provided in the wall sections of the bars which face the region between the glass panes to allow the desiccant material to absorb moisture from this region. The spacing frame corners, whether formed by butt-joining of the bar sections, using a miter cut, or by the use of separate corner pieces, are considered to be weak points in an insulating glass assembly, requiring careful working and special processing. Nevertheless, the known corner joints have been the subject of complaints, particularly in insulating glass pane assemblies which are exposed to extreme environments, for example, swimming pool enclosures or workshop areas.
German Pat. No. 2,160,847 discloses an insulating glass assembly which consists of two or more glass panes and a spacing frame arranged between the edges of the panes. The pane edges are joined to the spacer with a plastic compound, and the spacer has a bore extending longitudinally therein for containing a desiccant. A number of openings are provided in the spacer communicating between the longitudinal bore and the surface of the spacer which faces the region between the glass panes. The spacer forms the central longitudinal portion of a rigid bar, the bar having longitudinally extending grooves in its sides for receiving the edges of the glass panes. The bar therefore has a substantially U-shaped cross-section, the central portion of which includes the spacer with its central bore.
Assembly of the insulating glass assembly of German Pat. No. 2,160,847 is effected by inserting the edges of the glass panes into the outer grooves of the bar, and pressing the sides of the bar which bound the grooves against the glass panes. Such assembly is difficult, if not impossible, to realize in practice. For example, in order to properly seal the glass panes to the rigid bar including the spacer, the sides of the bar must be pressed against the panes. This pressing or rolling of the sides of the bar generally results in breakage of the glass panes. Also, this patent discloses the cutting of the bar in the form of a V at locations corresponding to the corners of the frames to be formed, and then bending the individual connected bar sections relative to each other. The bar is cut down to its base so that it is cut in V form over nearly its entire height at the corner regions to obtain a substantially mitered joint. This method of forming the frame corners is also undesirable due to the presence of the granules of desiccant provided in the central bore of the spacer portion of the bar. As soon as the V cuts are made, and the bar sections thus formed are handled to form the frame, the desiccant within the spacer portion of the bar will spill out from the central bore in the spacer, the bore having been opened to the outside by the V cuts. Inasmuch as a spacing frame for insulating glass panes must include desiccant to prevent moisture from forming on the inner surfaces of the glass panes, this method is, once again, not suitable.
An object of the present invention is to overcome the above and other shortcomings in the prior spacing frames.
Another object of the present invention is to provide a method of preparing tubular bars filled with granules of hygroscopic or desiccant material so that they can be bent to form spacing frames without providing V-shaped miter cuts in the bar.
In accordance with the present invention, a method of manufacturing a frame for use in forming an insulated arrangement of spaced glass panes from a continuous length of a tubular bar containing granules of hygroscopic material material of a given size includes cutting the wall section of the bar which is to form an inner frame border extending between the glass panes in a direction transverse to the longitudinal axis of the bar. The depth of each cut is selected to correspond substantially to the thickness of the wall section, and the width of each cut in the direction of the longitudinal axis of the bar is selected so that the granules of desiccant can not escape out through the cuts.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention .